Propeller



P. DLCESARE 3 Sheets-Sheet -1 4 PROPELLER Filed April. 27, 1933 P. mCESARE Wi" "1T 1,169

P'ROPELLER Filed April 27, 1933 '5 Sheets-Sheet 5 refilled with air.

siren STATE-s. PATENT ori-ICE PROPELLER Pierino Di Cesare, Chicago, Ill;

Application/April 27, 1933, Serial No. 668,181

16 Claims.

The invention relates to propellers and` more in particular to a novelpropellerconstruction adapted for use in air craft or for marinepurposes. The present application is a continuation `in part of mycopending application Serial No.

623,249, led July 18, 1932, an-d abandoned August 9, 1938.

Among the objects of the present inventionis to provide a novelconstruction of propeller for air craft and marine purposes which is ofgreater eflciency than those now being constructed and employed. In thepresent embodiment such increased efficiency is obtained withoutincreasing the size or dimensions of the propeller and Without addingany weight thereto, both of which are highly important factors inthedesign an-d construction of air and marine propellers.

A further object is to provide a novel construction of air or marinepropeller provided with a -central portion having a reduced passage oropening for receiving, guiding andejecting the` fluid acted on by thepropeller for propelling an airplane, vessel or other object, throughthe medium or fluid in which it is operating, whereby to increase theeniciency of the propellerover the` prior forms ofA propellers of thesame size, weight or material.

Another object of the invention is the provision cf a propeller forairplanes provided with anovel' f construction of hub and centralportion adding to the efliciency of the propeller. In the various formsof prior constructions the central portion around the hub serves nouseful purpose and inY fact creates a vacuum which naturally has to beThis vacuum tends to create a tremendous drag which has to be overcomeby the power of the engine. It has been quite commonly accepted that thevacuum createdby the inemcient central porti-on of the propeller was of`little importance and it has often been cited thatY this created vacuumwas of actual iiying aid as the engine and fuselage following lled inthis vacuum, but actual flying tests with such` prior forms ofpropellers and the present novel propeller construction have proventhatfsuoh is not the fact. By means of the present' invention, thisdisadvantage has been eliminated and the space behind the centralportion of the propeller is filled with air that is scooped up orcollected by the contour of the p-ropeller and exhausted or ejected intothe trailing vacuuml which is created as the aircraft is drivenforwardly.

A further object yof the invention is yto-provide a nevel propellerconstruction formed with a longitudinally extending passage, throat oropen ing` adapted to collect the approaching air and exhaust or ejectthe saine rearwardly off the pro# peller into the trailing vacuumcreated behind the propeller. This exhausted air forms a cool-V ingmedium adapted to `cool the engine.

Still another object of the invention is the provision of anovelpropeller in which the leading edge'cuts the air sharplysubstantially tothe center ofthe propeller, thereby `'greatly increasingthe efficiency and effective operative lengthV thereof yover priorpropellers'and those Whichare at the present time, standard equipment;

In such prior forms, a substantial partofthepropellers lengthconstitutes the central portion which effects a drag and at best has nooperative or advantageous effect in propelling the airplane. In thepresent novel` design;` substantiallythe entire propeller length iseffective in propelling the craft through theair;

Still another and further object of the invention 'is the provisionofapropeller that is substantially vibrationless in operation. In thepresent embodiment, this is accomplished byscoop'lng up and passing theair through the hollow central portion -cf the propeller whichfunctionsto balance and stabilize` the same. ThisA portion guides thescooped air and steadies the operation.

Numerous actual flying.v tests of' thepresent propeller have been madeand these tests have shown that aircraft equippedv with this typefofpropeller show a better response to 'the' controls. They;v also show `agreatly increased' performance and steady pull in climbing and the testsdisclose that an Iairplane equipped with the present propeller will takeoff or rise ata much less distance or in a smaller space than similarplanes equipped withthe prior or standardtypes of ,propellers Flyingtests at full throttle; and static thrust shcw a marked increase ineciency and speed, while stalling tests disclose thattheengine speed fmust be greatly decreasedor cut-dowrr before the plane will come toastall: These tests also show that the present type ofpropellerminimizes the danger of a tail spin since thereis'a more*`direct flow of air or air stream lwhich flows rearwardly along thefuselage and' stabilizes -the'pl-ane. All lof these tests vhave beenperformed'on sifni lar planes using both a standard `or-\pric`ircommercial type of propeller'and a propelleras 'dis-i closedin thepresent application-.h

The invention further consistsin',v and an ob-f ject thereof is toprovide a novel typefof-"adjustable hub construction or centralportion-ferai' propeller of the present "design or embodiment, in whichthe propeller hub and the centralseclv tion of the propeller is madeadjustable and the dimensions of the passage, throat or opening adjacentthe hub are varied, depending on the load or thrust imposed on thepropeller. This construction permits the utilization of the samepropeller for motors of varying sizes or horse power.

Another object is to provide a novel sectional hub construction in whichthe sections are automatically adjusted whereby to scoop or collectvarying amounts of air in the passages or pockets provided therefor andto eject such collected air laterally or rearwardly of the propeller.

A still further object of the invention is the provision of a propellerof this novel type provided with one or more longitudinally extendingpassages, throats or openings and which is admirably adapted for marineuse. Although the shape or contour of the blades of a propeller formarine use may vary somewhat over those for airplanes or other use, theprinciple involved and the function thereof is the same as in propellingan airplane,v even though it is operating in water. Increased efficiencyis secured by the use of this propeller over those now in standard usewhereby greater propulsion, speed and power is secured.

Further objects are to provide a construction of A maximum simplicity,efficiency, economy, and operation, and such further objects, advantagesand capabilities as will later more fully appear, and as are inherentlypossessed thereby.

The invention further resides in the combination, construction andarrangements of parts illustrated in the accompanying drawings, andwhile there is shown therein a preferred embodiment, it is to beunderstood that the same is susceptible of modification and change, andcomprehends other details, arrangements of parts, features andconstructions, without departing from the spirit of the invention.

In the drawings: Y

Fig. 1 is a View in rear elevation of the propeller construction;

Fig. 2 is a view in side elevation thereof;

Fig. 3 is a view in front elevation of the propeller;

Fig. 4 is a fragmentary view in perspective with the propeller sectiontaken in a plane represented by the lines 4 4 of Fig. 1;

Fig. 5 is a fragmentary view in vertical cross section taken in a planerepresented by the line 5-5 of Fig. 1;

Fig. 6 is a fragmentary view in perspective of the central portion ofthe propeller;

Fig. 7 is a view in vertical cross section through a. modified form ofpropeller in which the central section thereof is made adjustable;

Fig. 8 is a fragmentary view in vertical cross section taken through thehub and central section of the construction similar to that shown inFig. 7, but showing the position of the telescoping members of thepropeller when there is little or no load imposed thereon.

Fig. 9 is a view in vertical cross section through the adjustablecentral section and hub taken in a plane represented by the line 9-9 ofFig. 7;

Fig. 10 is a fragmentary view in rear elevation of the adjustable huband central section;

Fig. 11 is a fragmentary view in perspective of the adjustableconstruction;

Figs. 12 and 13 are slightly modified forms of telescoping sections;

Fig. 14 is a view in rear elevation of a marine propeller;

propeller;

Fig. 16 is a view in perspective thereof;

Fig. 17 is a view in vertical cross section taken in a plane representedby the line ll-l'l of Fig. 14; and

Fig. 18 is a fragmentary view in vertical cross section of an alternateform of marine propeller in which the hub is positioned exterior of thebody of the propeller.

Referring more particularly to the drawings and specifically to thedisclosure in Figs. l to 6 of the drawings, the embodiment selected toillustrate the invention in these figures comprises propeller I havingoutwardly or oppositely extending blades 2 formed with a leading orcutting edge 3. This propeller may be employed to propel an airplane orother aircraft by either pulling or pushing it through the air. In theprior designs of` propellers and those which are now standard orcommercial equipment for airships or other aircraft, a great part, andin most instances substantially thirty-five percent of the propellerlength comprises the central section which is at best ineffective andhas no useful function in propelling the aircraft through the air.

In the pres-ent embodiment, this leading edge 3 and the effectiveoperative portion of each blade extends for substantially the fulllength of the blade so that the effective surface area thereof isgreatly increased.

As clearly disclosed in Figs. l to 6 inclusive, the blades are dishedadjacent the central portion and this dished portion or depression 4communicates with a passage, throat or opening 5 ntermediate the outerplate 2'fl carrying the blades and the inner plate 6 adjacent the hub laof the propeller. This ldished portion or depression forms a pocket forcollecting the air acted on by the propeller blade and directs the airinto the reduced passage or throat 5 from where it is exhausted orejected laterally or rearwardly of the propeller. This form ofconstruction not only gives greater surface area or effective operativesurface of the propeller blade for acting upon the air or fluid in whichit is operated, but collecting and scooping up of the air and thepassage thereof through the passages 5 gives greater efficiency andpropulsion to the propeller. This ejection of the air laterally of andrearwardly of th-e propeller eliminates any possibility of forming avacuum behind the central part of the propeller. It further stabilizesthe operation of the propeller whereby to reduce or eliminate vibrationthereof, and the stream of air passing rearwardly toward and along thefuselage of the airplane tends to stabilize the same in its travel.

The construction of the propeller may comprise an integral member or itmay consist of sections as shown in Figs. 7 to 13 inclusive. In thisconstruction, the blades 1 are made similar in contour to those shown inFigs. 1 to 6 inclusive, and each blade is provided with a dished portionor depression 8 adjacent the hub for collecting the air and directing itthrough the passage 9 from where it is ejected or exhausted laterally orrearwardly.

Each passage or throat 9 is made adjustable, the size thereof dependingupon the load or thrust of the propeller. In Fig. 8 there is disclosedthe position of the adjustable section when little or no load is imposedupon the propeller, while in Fig. '7 the parts are `disclosed when thereis a full load, in which case the passage or throat is reduced in crosssection.

In order to permit an adjustment of the passages 9, the propeller ismade sectional, the for- WarilV ,or` outer section `I ll carrying the,blades l and is slidable or movable longitudinally of the driveorpropeller shaft II. The rear section I2 is mounted stationary on thedrive shaft and is provided with an upper and lower forwardly ex- Atending flange I3 adapted to receive therein or therebetween therearwardly extending flanges I4 of the front section I0. Thus thesemembers telescope together and are adapted to form therebetween theadjustable passages or throats 9 for thepassage of and ejection of theair acted on and `collected by the blades and which air is guided.therethrough by reason of the depression or dished portion 8 adjacentthe hub. The hub construction is likewise made sectional and comprises aquill or inner stationary hub part I5 mounted on the propeller or driveshaft II by means of a key I6, This stationary hub I5 at its forwardendabuts against a collar or stop member I'I which is threaded onto theshaft. A washer I8 and a nut I9 are adapted to secure this collar orstop in position and prevent it from backing ofi of the threaded end ofthe propeller shaft. The stationary hub part I5 is splined, being formedwith ribs 2B having grooves k2i therebetween. These grooves 2| areadapted to receive ribs or utes 22 and the ribs or utes 2e are adaptedto be received in channels 23 in a slidable or movable hub member 24which is adaptedto encompass and slide on the inner stationary hub I5.

Thus the inner and outer hub members l5 and 24 respectively, provide asplined construction in which the members are provided withcomplementary surfaces so co-related and coacting to permit relativelyfree sliding movement therebetween. If desired, coacting faces betweenthe complementary members may be provided with races adapted to receivebearings 25. The outer hub member 24 is provided with an annular ange 26adapted to be connected to the front plate le by means of bolts or othersuitable retaining means 2'I. A rear hub plate 28 is mounted on thereduced end 2,9 of the inner hub member I5 and is suitably connected tothe inner plate I 2` by bolts or other retaining means 3l). A retainingor lock nut 3l is adapted to be threaded onto this reduced end 29 and tolock the hub plate 23 and plate I2 stationary upon the drive orpropeller shaft II.

Mounted within the passages or throats 9 is a coil spring 32A adapted tobear against the inner faces of the plates I and I2 and exerting acompression against the plate Il! tending to force this plate and theblades formed thereon or carri-ed thereby, outwardly, as disclo-sed inFigure 8, the pressure of the air against the propeller overcomingwhatever screw action there might be present to force the section I eoutwardly. When the propeller is operated under load, the plate I0 isforced inwardly and the spring 32 takes this rearward thrust. Since thisspring 32 is mounted within the passages 9 and the air which passestherethrough, this spring is provided with a leather or other flexiblecovering 33. A spring 34 mounted on this covering is adapted to keep thecovering expanded against the opposite side walls so as to at all timescover the springs against the entrance of dirt or other foreign matter.

As the spring 32 is? of considerable compression and tends to force theplate I0 andthe movable hub 24 outwardly, the invention comprehendsl theprovision of a spring 35 seating against the annular ange 26 and anannular flange 36 ,formed on the collar Aor, stopirnemloerll l.. Thisspring acts as a shock absorbers@ as torreventthe spring 32 from forcingthe, plate In outwardly with too great aforoe, thuslpreventing danger ofthe movable `hub. member 2,4 from striking against the collar Il.whentheload is removed ,from the propeller. A cover or housing 3l`isadapted to enclose the nose or front portionA of the hub so as toprevent the entrance of water, ice, dust and other foreign matter. Thisnose., housing or cover is detachably secured to the annular flange 26by bolts or other sutableretaining means 38. From the above disclosure,it willbe readily seen that by varying the strength or compression ofthe spring` 32, the saine propeller may` be utilized for engines ofvarious sizes orl horse power. It will also be clearly evident; that thediameter and pitch of the propellerV remain constant even though thesectionsor platesIU and I2 forming the propeller are shiftable o1'movable relative to each other.

In Figs. 12 and 13 are disclosed modications of the telescopic plates.In Fig. 12 the outer plate III@L is provided with upper and lowerflanges 39 adapted to receivethe flanges 40`of the inner plate I2a.Thisl construction is similar to that shown in Figs. 7 and 8, with theexception that the flanges of theouter plates are exterior of andadapted to receive the flanges on the inner plate, rather than thereverse construction as disclosed in the prior figures.

In Fig. 13 the outer plate is similar in construction to thatdisclosed'in Fig. 1.2 while the inner plate 4I is devoid of upper andlower flanges. In this construction the plate itself is received withinthe flanges 39 of the `outer plate I lla and which anges are adapted toslidev or move thereover.

In Figs. 14 to 18 inclusive, there is disclosed a propeller. quitesimilar inoperation and function as the propeller disclosed in Figs. 1to 6 inclusive, but in which the contour has been altered in order toadapt it for marine purposes. Since this propeller functions to push aboat or other vessel through the water or medium in which it isoperating, the mounting thereof is reversed from that of the airplanepropeller in which the rear plate 6 faces the front-ofthe fuselage. Werethis type of propeller used in pushing a plane through the air, theplate 6 would necessarily face in a reverse direction so as to pushrather than pull the airplane through the atmosphere. In the marine typeof propeller, the rear plate 42 extends or faces away from the boat.This marine propeller is shown as provided with a pair of blades 44provided with a leading edge 45. Throughout a substantialportion of thelength of these blades, they are dished or concaved as at 46 whereby toscoop up the water or iiuid being acted upon and direct and project thisfluid through a throat or passage 4l extending adjacent the hub 48 ofthe propeller. The water or iiuid passing through the throat or passage41 impinges against the side walls 49 thereof, and helps to rotate thepropeller. The water which is discharged or ejected from the throat 4lwill pass laterally therefrom in a manner similar to that of the ejectedair in the preceding disclosures, due to the constructions, contour androtation of the blades and throat and the direction of travel of thevessel or structure being propelled.

This ejection adds greater efficiency and pushing power to thepropeller, whereby the speed at which the motor is turning over may bereduced, ora smaller motor may be provided to accomplish the same powerand speed as a larger motoremploying the` prorand `standard types of vt0 a large extent.

propellers. The discharge or ejection of the water or uid gives addedhydraulic propulsion.

'In Fig. 18 there is disclosed an alternate form of marine propeller inwhich no interior hub is provided but the hub is exterior of thepropeller and comprises an outer boss or hub member 50 and an inner bossor hub Vmember 5I suitably keyed to the shaft 52. A lock nut 53 retainsthe propeller in adjusted position. It is of course t0 be understoodthat the propeller shaft 52 need not pass through the body of thepropeller but a bearing member or hub may be provided exterior thereofon one of the plates, whereby leaving unobstructed the passage throughthe propeller.

With the clockwise rotation of the propeller as shown in Figure 1, thefluid will enter both throats or openings 5 in opposite directions, bothtowards the center. Due to the direction of rotation, the fluid of theright hand throat will be compressed against the upper right portionthereof, while a partial vacuum or void will exist in the upper leftportion at the point of application of the dotted line from 5; theopposite conditions prevailing as to the lower portion of the throat.Thus it will be seen that the uid will pass through the throat inopposite directions but on opposite sides of the shaft and interferencebetween the two oppositely flowing currents will be avoided The sameconditions and operation are found in the adjustable and marinepropellers.

Although a greater efficiency is secured by the use of my propeller, thevoyage is smoother since s the agitation of the water is greatlyminimized and the wake and swell following a vessel equipped with thenovel propeller is noticeably decreased.

When the novel propeller is used on an airplane or for propelling air,the construction and design is such that in scooping or collecting theair and discharging or ejecting it from the longitudinal central portionof the propeller, the noise or metallic sound emitted is greatlyminimized. This sound is generally caused by the broad surfaces of ltheblades striking the air and thereby causing vibration which istransmitted to the tip of the blades and thence to the atmosphere. Inthe present construction such broad surfaces are not present. v

From the above description and the disclosure in the drawings, it willbe readily seen that the invention comprehends a unique or novel form ofpropeller in which the design, contour and construction thereoi greatlyincreases the efficiency over prior types of propellers. Thus, withoutincreasing the size or weight of the propeller and in fact reducing theweight thereof, because it requires less material, this inventionpermits a decrease in the size of Vpower plant or an increase in thepower and speed with the same power plant.

Although I have disclosed the propeller as particularly adapted forpropelling aircraft or boats, it is to be understood that it is equallyas well adapted to propel any other structure in which a propeller maybe employed, or for propelling currents of air or other fluid.

Having thus disclosed the invention, I claim:

l.. A propeller provided with propelling blades and a central portionhaving a hub for connecting the propeller to the drive shaft, andtelescoping sections at said central part adapted to be adjustedrelative to each otherV and so constructed and arranged as to provide anadjustable outlet from the eifectivesides of said blades for directingand ejecting fluid collected therefrom.

2. A sectional propeller construction adapted to be mounted on a driveshaft and rotatable therewith, comprising a plate fixed on said driveshaft and a plate slidable longitudinally thereon, said slidable platecarrying the propelling blades.

3. A propeller construction adapted to be mounted on a drive shaft,comprising a pair of members rotatable with said dn've shaft but movablerelative to one another and longitudinally of said shaft, one of saidmembers carrying the propelling blades and said members being spacedapart to form a fluid passage therebetween.

4. A propeller construction adapted to be 'mounted on a drive shaft androtatable therewith comprising propelling blades, an adjustable centralsection provided with telescopic parts providing a passage 'therebetweenthrough which fluid acted on by said blades is directed and ejected,said passage being automatically adjusted by the load imposed on thepropeller.

6. A propeller construction adapted to be mounted on a drive shaft androtatable therewith comprising propelling blades, an adjustable centralsection provided with telescopic parts providing a passage therebetweenthrough which fluid acted on by said blades is directed and ejected,said passager being automatically adjusted by the load imposed on thepropeller, and compression means tending to extend and separate saidparts.

7. A propeller construction adapted to be mounted on a drive shaft androtatable therewith comprising propelling blades, an adjustable sectioncentrally of said propeller and provided with parts adapted to beautomatically adjusted to provide a passage therebetween of varyingcross section depending on the load, means acting against the loadtending to separate said parts and increase said cross section, andmeans acting to absorb any shocks to said parts resulting from a suddendecrease or removal of the load on the propeller.

8. A power-driven propeller for aircraft and marine use provided withoutwardly extending blades, a member spaced from said blades and apassage intermediate said blades formed by said blades and member forreceiving the fluid being acted on by the body of said blades and saidpassage communicating with the rear face of each blade, the rear face ofsaid blades being so constructed and arranged as to collect fluid actedthereon and directing it toward the passage, said passage receiving andejecting said uid away from the blades.

9. A power-driven propeller provided with blades adapted to act upon theud in which it is operating, a plate spaced from said blades, and atapered passage formed by said blades `and plate and located centrallyof said blades and communicating with the rear face of each blade foraxially directing and discharging from the propeller the fluid beingacted upon and collected by the blades.

V10. A power driven propeller provided with spaced plates, one of whichforms the propelling blades, a hub therefor, and a passage intermediatesaid plates and communicating with the rear face of said blades, saidblades being so constructed and arranged that fluid acted upon andcollected by said rear face is directed inwardly from the ends of theblades and toward the hub and ejected through said passage for thepurposes set forth.

11. A power-driven propeller for aircraft and marine use provided withoppositely extending blades and a plate spaced from said blades, a hubtherefor, and a tapered passage formed by said blades and plate onopposite sides of the hub and communicating with the rear face of eachblade, said passage forming an outlet adjacent the hub for the fluidcollected by the rear faces of said blades and directing and ejectingsaid collected fluid therethrough.

12. Apower driven propeller for aircraft and marine use provided withoppositely extending blades and a member spaced fromV said blades, a hubtherefor, and a tapered passage formed by said blades and member at therear face of said propeller and extending on the opposite sides of saidhub and longitudinally of the blades, the rear face of said blades beingso formed as to collect and direct the fluid acted upon, inwardly fromthe ends thereof to the hub and through said passage into the spacebehind the propeller.

13. A propeller for use onairplanes provided with a hub adapted toreceive the drive shaft and blades extending outwardly therefrom forpropelling the airplane through the air, the central portion of saidpropeller connecting said blades being provided with a member spacedfrom the blades and forming an opening communicating with the rear facesof said blades and adapted to collect the air acted on by the rear facesof said blades and direct it inwardly toward the hub and through saidopening and then rearwardly into the space directly behind saidpropeller.

14. An airplane propeller provided with a central part adapted to beconnected to the drive shaft, blades extending outwardly from saidcentral part for propelling the airplane through the air, said bladeshaving their rear face dished to scoop and collect the air adjacentthereto and said central part being provided with a member spaced fromthe blades and dening a passage therebetween, the air collected by saiddished blades being directed inwardly to said passage and ejectedtherethrough and rearwardly therefrom into the space behind the centralpart to eliminate any tendency of the propeller to form a vacuum in saidspace.

15. An airplane propeller provided with a central part having a hub forconnecting it to the drive shaft, blades extending outwardly from saidcentral part and adapted to propel the airplane through the air, a platespaced rearwardly of said blades, said part being provided with atapered opening formed intermediate said blades and plate andcommunicating with the blades,

said blades being dished adjacent said opening to collect the air anddirect said collected air inwardly towards the central part and throughthe opening and eject it into the space behind the central part of thepropeller so as to lill said space with the collected air and preventthe formation of a vacuum thereat.

16. A propeller comprising outwardly extending blades adapted to actupon the fluid in which the propeller is operating, and an adjustable'nnb construction therefor including telescopic members adapted to forma passage therebetween to receive uid acted on by the blades and todirect said fluid rearwardly of the propeller.

PIERINO DI CESARE.

